My program gives right answer all tests in the forum but T've got WA#2.Please give me some test
Thanks

Oh,I got AC now!

I have WA #2 too.
Can you give me some tests?

Some tests:
1 100 2 4 ->6
1 300 4 8 ->0
1 400 4 2 ->111
You can use this full search program to check:
//////////////
var
        x,y,k,b,p,q:longint;

function kt(s:longint):longint;
var
    a:array[1..40]of longint;
    sd,i,j:longint;
begin
        sd:=0;
        repeat
                inc(sd);
                a[sd]:=s mod b;
                s:=s div b;
        until s=0;
        j:=0;
        for i:=1 to sd do
        if a[i]=1 then inc(j)
        else if a[i]>1 then begin kt:=0; exit; end;
        kt:=j;
end;

begin
        read(x,y,k,b);

        p:=0;
        for q:=x to y do
        if kt(q)=k then inc(p);
        writeln(p);
end.
/////////
Good luck!

Thank you Saturn.